by Nate Davis, USA TODAY Sports

by Nate Davis, USA TODAY Sports

To top the San Francisco 49ers, the Baltimore Ravens will need to do what they do best - and shore up a long-running trouble spot.

Stop the run: The Baltimore defense is as healthy as it's been all season, the year-ending injuries to CB Lardarius Webb and ILB Jameel McClain aside. But the Ravens' struggles against the run have only intensified in the playoffs (128.3 yards per game) despite playing three teams with pocket-bound passers. That will change Sunday when they face long-striding QB Colin Kaepernick, bullish back Frank Gore and the 49ers' pistol offense. San Francisco is averaging 236 yards on the ground in postseason, including 323 against the Green Bay Packers, who favor a 3-4 defense like Baltimore. Ray Lewis, Terrell Suggs, Haloti Ngata and Co. will have to ward off age and injuries to bottle up a genie that's close to granting the Niners a sixth ring.

Attack the corners: As good as San Francisco's defense has been in recent years, it can falter in pass coverage. A year ago, the Niners survived the New Orleans Saints despite allowing three 100-yard receivers in a divisional round shootout. A week later, Victor Cruz worked over CB Carlos Rogers for 10 catches and 142 yards in rainy, windy conditions in the New York Giants' NFC Championship Game victory. The 49ers continue to toe a dangerous line on the passing periphery. They gave up some big plays to Green Bay in this year's playoff opener and even more to the Atlanta Falcons the following week as Julio Jones and Roddy White frequently ran free. Baltimore WR Torrey Smith can stretch any secondary while wingman Anquan Boldin overpowers most corners. If Jacoby Jones can also threaten the deep zones, the Ravens should be in business. And forcing the 49ers into nickel packages dilutes their outstanding front seven while opening cracks for Ray Rice and underrated TE Dennis Pitta.

Protect the quarterback: Joe Flacco can't run like Kaepernick, but by nearly every other metric, the rocket-armed Raven has been the postseason's top passer. His 114.7 rating is tops in the playoffs - 27 points higher than his regular-season clip - and he has yet to throw an interception while firing off eight TDs. Yet the job Baltimore's reconfigured offensive line has done isn't getting enough attention. LT Bryant McKinnie (all 354 pounds of him) didn't start once in the regular season but returned to the lineup in January. Even though his presence forced Michael Oher and Kelechi Osemele to switch positions, the unit has thrived, surrendering just 1.3 sacks of Flacco per game - about one fewer than he endured in the regular season. If Flacco has time to exploit an already suspect San Fran pass defense, look out.

Maintain discipline: Despite their veteran pedigree, the Ravens were the most-penalized team in the NFL in 2012 and committed a league-high 19 personal fouls. Lewis and hard-hitting SS Bernard Pollard were whistled for excessive hits in the AFC Championship Game. Sometimes playing on the edge can send a lesser opponent over it, and Pollard's (legal) blow on New England Patriots RB Stevan Ridley turned the tide two weeks ago. But costly miscues can also prove fatal in games with razor-thin margins and evenly matched foes. Gap discipline will be just as vital in Baltimore's quest to prevent Kaepernick and Gore from breaking off long gainers.

Cover the kicks: If not for two return touchdowns by Trindon Holliday, the Ravens might have blown the Denver Broncos off their Mile High mountain in the divisional playoffs rather than outlasting them in double overtime. Baltimore also struggled to contain New England's Wes Welker on punts in the AFC Championship Game. But the Ravens are also perfectly capable of suffocating kick coverage and didn't allow a single return to the Indianapolis Colts in the wild-card round. Rookie K Justin Tucker should get plenty of distance on his kickoffs in the Superdome, but Sam Koch will need to improve his hang time and directional punting. After all, 49ers return man Ted Ginn Jr. can hit a home run at any time.